The typical front wheel drive tractor has one or more service points such as the gasoline inlet or coolant inlet, located on the top front portion of the engine housing. As a result, the tractor operator or someone servicing the tractor must routinely gain access to the top front portion of the vehicle. At the present time, there is no convenient way to get to this portion of the vehicle, which may be 6 or more feet off the ground. Bringing along a stool or ladder to stand on is inconvenient and often impractical when the tractor is in the field. Therefore, an operator or someone servicing the tractor will use the tractor body, front wheel, or steering elements of the tractor to gain access to the upper portion of the vehicle.
Consequently, the typical method of servicing finds the operator standing on the front wheel or front axle of the tractor. On many row crop tractors and on high clearance tractors, the front axle or tire may be several feet or more off the ground. On such tractors, the operator will attempt to step up to the top of the front axle or tire by using the wheel rim or hub as a foot hold, a very inconvenient procedure.
The problems of gaining access to the front of the vehicle are further complicated by the arrangement of the front axle and steering components and the presence of additional equipment both of which restrict access to the front of the tractor. In addition to making access difficult, the wide front axle arrangement and equipment attachment poses additional problems in providing a foot hold or step to improve access. The usual front axle arrangement has the front wheel supported from a generally vertical knee having a small outward slope from top to bottom. The knee is attached at its upper end to an adjustable axle section which bolts to the main portion of the front axle. When desired, the adjustment between the front wheels may be made very narrow providing little room between the front wheels and the outside of the vehicle chassis. In most cases, access to the axle from the rear of the tractor is prevented by a steering arm that projects out from the top of the axle to the rear of the tractor. In looking at the front of the tractor for access, the front counterweights used to adjust the weight distribution on the tractor are in close proximity to the wheels thereby providing additional interference. Finally, the clearance between the front wheel and the vehicle chassis is further restricted at times by the addition of equipment to the front end such as loaders or cultivators which are bolted onto the outside of the frame thereby extending its width. Thus, in many instances, access to the front of the tractor front axle is extremely restricted.
One means of making the general area of the front axle more accessible is to turn the front wheels outward thereby increasing the open area in the vicinity of the front axle. This method has been used particularly on front-wheel drive tractors having steerable front wheels with service steps added to the front axle of such tractors to further facilitate servicing the front end of the engine housing. However, this method, in the addition of a step to the front axle, does nothing to help one get from the ground to the axle or tire.
For two-wheel drive tractors which have a knee portion, the addition of a step to the lower portion of the knee would greatly facilitate access to the top of the front axle or wheel. Up until now, service steps have not been added to the knee portion due to clearance requirements and the close proximity of the inner portion of the wheel to the knee. In regard to clearances, it is unacceptable to have any projection from the knee extending into the area below the front axle and between the tractor knees. This area must be kept clear to prevent damage to emerging crops when the tractor is driven between crop rows. In addition, the wheels are purposely spaced close to the knee to reduce the overall profile of the knee and tire assembly thereby keeping the overall tire path area to a minimum. Accordingly, attachment of a service step to the lower portion of the tractor knee was thought to have limited utility due to the apparent lack of clearance. It has now been found that a useable service step which provides sufficient area for convenient access to the front axle or wheel, despite the presence of front end equipment, can be located on the knee portion of the tractor without decreasing crop clearance or increasing the wheel and knee profile.